Type basket and type lever mounting



Aug. 18, 1959 H. l.. THoLsTRUP v TYPE BASKET AND TYPE LEVER MOUNTING Original Filed Oct. 4, 1956 2 Sheets-Sheet 1 IN VEN TOR. #5A/Hy l, 7AM shea/7 A 77o RNEV Aug. 18, 1959 H. 1 THoLsTRUP TYPE BASKET AND TYPE LEVER MOUNTING Original Filed Oct. 4, 1956 2 Sheets-Sheet 2 E lll m. w m m ATTORNEY United States Patent i TYPE BASKET AND TYPE LEVER MOUNTING l Henry L. Tholstrup, Rochester, N.Y., assignor to Commercial Controls Corporation, Rochester, N.Y., a corporation of Delaware Original application October 4, 1956, Serial No. 613,877. Divided and this application October 2, 1957, Serial No. 687,693

3 Claims. (Cl. 197-39) This invention relates to improvements in power operated character-by-character printers, and constitutes subject matter divided from my copending application for United State patent, Serial No. 613,877, tiled October 4, 1956, for Power Driven Printer.

The printer of my aforesaid application for patent is capable of very high operational speed by reason of the fact that it provides a positive drive for the type levers, carriage, etc., thus overcoming acceleration lags inherent in machines in which type lever action is merely power initiated and in which the return movement is under the influence of gravity or light spring tension, or in which carriage movement is merely under control of springs.`

By providing mechanism for the positive movement of both type levers and carriage, in both directions, the printer of my aforesaid application has an average type bar speed of only 40 milliseconds, the carriage can be returned (100 spaces) in 480 milliseconds, tabulation can be performed (50 spaces) in 296 milliseconds, the shifting operation consumes only 40 milliseconds and the back space operation can be performed in l milliseconds, with the result that the typing strokes for average copy are increased to 35 or more per second.

It can be appreciated that type levers that operate under positive driving power in both directions and at very high speed are subjected to stresses greater than those present in conventional typewriters. These greater stresses must be taken into consideration in designing type basket structures and the means for mounting the type levers therein.

It is the primary object of this invention, therefore, to provide improved mechanism for mounting type levers in a power operated printer.

The principal object of the invention is attained by providing individual means for mounting each type lever such that conventional fulcrum wires are eliminated. The invention further provides a type lever segment structure -which is adapted to receive and engage with equal pressure the individual fulcrums of a complement of type levers.

Further objects and advantages of the invention 'will become apparent as the specification is read in'light of the drawings forming a part hereof, in which drawings like reference numerals indicate like parts, and in which:

Fig. 1 is a sectional view through the power operated printer in which the invention herein has been embodied;

Fig. 2 is a fragmentary plan view of a type basket segment taken on line 2 2 of Fig. l

Fig. 3 is a sectional view on line 3 3 of Fig. 2; and

Fig. 4 isI a sectional view on line 4-4 of Fig. 2.

By reference to Fig. l, it will be seen that a complement of type levers is mounted in a type basket 12 such that each type lever can be rotated into and out of a common printing position ywith respect to a platen 14 mounted on a carriage 16. The speed at which the type levers are adapted to operate precludes the use of a conventional segment wire for mounting the type levers in the type basket.

Consequently, this invention contemplates an improved means for mounting the individual type levers in the type basket such that the operational strain of the positive drive can be successfully absorbed.

Figs. 2 through 4 show type lever and type basket structures adapted to this end. Each of the type levers 10, as best seen in Fig. 4, has a pivot point in the type basket 12 consisting `of a small ball 18 which is swaged into an eye at the inner end of the type lever. The type basket is segmental in form as in the usual typewriter structure and consists of a base segment 20 and a locking segment 22 (Fig. 2). Each of the segments 20 and 22-has complementary hemispherical concavities forming a bearing pocket 24 (Fig. 3) for the type lever bearing balls 18. The bearings balls 18 of` a complement of type levers are seated in the conca'vities of the base segment 20 and are there held in place by the locking segment 22 which is iixed to the base segment 20 by means of a series of screws 24.

ln a machine adapted to high speed operation, such as the present machine, it is important that each lof the type levers be retained in the type basket under substantially the same amount of pressure. In order to accomplish this particular result, the locking segment 22 and particularly that part which engages the pivot balls 18 assumes the form of a rim 26 which has a slot 28 milled therein, thereby imparting a degree of resilience to the rim 26 under which the type lever pivot balls 18 are engaged.

By reference to Fig. l, it can be seen that each of the type levers 10 has formed at the pivot end thereof a gear segment 30. Each type lever gear segment 30 is constantly in engagement with mating teeth 32 of a related bell crank 34. It may be seen, therefore, that whenever the bell crank 34 of Fig. l is rotated in a counterclockwisedirection, the type lever 10 which is associated there- With, will be rocked in a clockwise direction which is the printing stroke. When the bell crank 34 is rocked in a clockwise direction, the type lever associated therewith will be rocked in a counterclookwise direction thereby returning the type lever to its normal inoperative position of rest against a type lever stop 36. The pivot balls 18 provide for the free rocking of the type levers 10 in either direction and impart a stability to type levers which has heretofore been unattained. The mechanism by which the bell cranks 34 are operated and controlled will now be described. In this connection, it is to be understood that each type lever of the entire complement of type levers is operated by a bell crank assembly such as that shown in Fig. l.

The bell crank 34 is mounted for rocking movement on a bell crank shaft 38 and associated with which bell crank is a drive plate 40 fixed for rotation with aconstantly rotating power shaft 42. Extending from one face of the drive plate 40 are a pair of drive pins 44 and 46. These drive pins are adapted to cooperate with elements of the bell crank 34 to drive the bell crank, all as more fully set out in my aforesaid application for United States patent.

The bell crank 34 carries a bell crank latch 48, a guide plate 50, a stop pawl 5'2 and a pair of lugs 54 and 56. The bell crank latch 48 is pivoted on the bell crank 34 by means of a pivot pin 58. The bell crank latch 48 is biased about the pivot pin 58 in a counterclockwise direction by means of a spring 60 which extends between the free end of the bell crank latch 48 and the bell crank 34. The bell crank llatch 48 is normally held in retracted position, as shown, by a bell crank trip lever 62. The bell crank trip lever 62 is pivoted on a trip lever shaft 64 about which it is normal-ly biased in a counterclockwise direction by `a spring 66 connecting the upper end of the bell crank trip lever 62 with a casing 68 in which the bell crank assembly is located. The bell crank trip lever is generallyA L-shaped and has an inwardly extending leg 70, which at its free end has a downwardly extending finger 72 adapted to engage a latch point 74 at the lower end of the bell crank latch 48. While the nger 72V and the latch point 74 are engaged, the bell crank latch 48 will be in its retracted position against the tension of the spring 60.

It has been stated heretofore that the power shaft 42 is rotating constantly with the result that the drive plates. 40 also rotate constantly. So long as the bell crank latch 48 is in its retracted position, the pins 44 and 46 of the associated drive plate 40 will rotate freely in respect to the bell crank 34. In this connection, it should be noted that the-pins 44 and 45 extend into proximity with the face of the bell crank 34 such that if the bell crank latch 48 is released, its lower-free end will be engaged by either of these pins with the result that the bell crank 34 will be driven in a counterclockwise direction about the bell crank shaft 38.

In order to control the operation of the bell cranks there have been provided key magnets 76, one for each bel-l crank, arranged in two staggered rows across the front of the printer. Each key magnet has a trip pin 7S in contact with an armature 80. Thus, for example, if the magnet 76 isl energized, it will attract its armature 80 and thereby move the associated trip pin 78 rearwardly. The armatures 8i) are normally heldA away from their related magnets by means of a spring 82. The trip pin 78 when operated by reason of energization of its related key magnet, will rock the bell crank trip lever 62 in a clockwise direction `about the trip lever shaft64. This will serve to release the bell crank latch 4S so that its spring 60 will rotate the latch 48 in a counterclockwise direction about its pivot 53 and thereby project the free end of the bell crank latch 48 into the path of the drive pin 46, for example, thereby conditioning the bell crank 34 for operation. The tension of the spring 66 which is, connected to the bell crank trip lever 62' is sufhcient to return the trip pin 78 to its normal inoperative position when its related armature 80 is releasedV by the key magnet 76.

`The key magnets are conventionally under control of a punched paper tape reader and code translating system, such as that shown in my Patent No. 2,461,451, issued February 8, 1949. In tape reading systems of this general category, a plurality of transversely arranged character representing holes are sensed and the combinational code so sensed is translated to produce a single impulse representative of a character. These impulses are conducted to the key magnets of the present invention by means of suitable electrical conductors Y connected to the individual key magnets corresponding to the characters represented by the several impulses. T'he specific manner in which the power is applied to the power shaft 42, and also the way in which the drive mechanism is controlled is more fully disclosed in my aforesaid application for United States patent.

In accordance with the provisions of the patent statutes, I have described the principle of operation of the in: vention, together with the elements which I now consider the best embodiments thereof, and what I claim as my invention are these embodiments and such modications thereof `as may fall within the scope of the following claims.

I claim:

1. Ina power operated typewriter, a segment for mounting type barsY comprising, a base member having slots through one edge thereof to receive type bars, a clamping member having corresponding slots, said members having complementary bearing seats intersecting the slots thereof, means for securing said members together with the slots and bearing seats thereof in registration, type bars mounted independent of each other for oscillation in said segment, each of said type bars having a bearing seated in one of said bearing seats formed between said members, and a peripheral slot in one of said members disposed in perpendicular relationV to the rst named slots therein and extending beyond said bearing seats therein.

2. In a power operated typewriter, a segment for mounting type bars comprising, abase member having slots through one edge thereof to receive type bars, a clamping member havingl corresponding slots, said-members having complementary hernspherical bearing seats intersecting the slots thereof, means for securing said members together with the slots and bearing seats thereof inregistration, type bars mounted independent of each other for oscillation in said segment, each of said type bars having a bearingy ball seated in one of said bearing seats formed between said members, and a peripheral slot in one of said members disposed in perpendicular relation to the first named slots therein and extending beyond said hemispherical bearing seats therein.

3. In a power operated typewriter, a segment for mounting type bars comprising, a base member having slots through one edge thereof to receivel typebars, a clamping member having corresponding slots, said-members having complementary hemisprerical bearing seats intersecting the slots thereof, means for securing said members together with the slots and bearing seats thereof in registration, type bars mounted independent of each other for oscillation in said segment, each of said type bars having a bearing ball seated in an aperture at one end thereof and said ball being seated inV one of said bearing seats formed between said members,'and a peripheral slot in one of said members disposed in perpendicular relation to the first named slots therein and extending beyond said hemispherical bearing seats therein.

References CitedV in the le of this patent UNITED STATES PATENTS 755,404 Smith Mar. 22, 1904 FOREIGN PATENTS 524,559 France May 16,1921 

